To me, this was one of the most interesting things about the Beolab 90.
The Beolab 5 design is based on what's generally accepted, that we want narrow vertical directivity and wide horizontal directivity. That type of setup allows for good sound, no matter if you're on or off axis.
The Beolab 90 throws that out the window; in the 'narrow' setup it's basically optimized for a sweet spot.
But I found that worked a lot better; I heard imaging that's about as good as it gets, and though I've heard hundreds of speakers there are only two or three that could image as well as the Beolab 90. And the other speakers that imaged like that didn't have bass that was in the same league as the Beolab 90.
TLDR: I wonder if narrow horizontal directivity is more important than narrow vertical directivity? Beolab 90 seems to indicate this is true.
But in balance, everyone was also wowed by the Kii3.
Most startling, earth-shifting presentation: Bruno Putzeys' compact, stand-mounted Kii Three speakers powered internally by his class-D amp modules—one amp and one DAC per driver (six in all). Deep bass into the mid 30Hz region, sweet, extended highs. $13,900/pair. Amazing.
Kii Audio's Model 3 speakers, slightly larger than most bookshelf two-way systems, reminded me of the BeoLab90 in a much more compact package (6 drivers, 6 DACs, 6 NCore class-D amplifiers per cabinet) at one-fifth the price
I suspect Kii will shift a lot more than B&O, and of course yamaha 1000 times as many
Most startling, earth-shifting presentation: Bruno Putzeys' compact, stand-mounted Kii Three speakers powered internally by his class-D amp modules—one amp and one DAC per driver (six in all). Deep bass into the mid 30Hz region, sweet, extended highs. $13,900/pair. Amazing.
Kii Audio's Model 3 speakers, slightly larger than most bookshelf two-way systems, reminded me of the BeoLab90 in a much more compact package (6 drivers, 6 DACs, 6 NCore class-D amplifiers per cabinet) at one-fifth the price
I suspect Kii will shift a lot more than B&O, and of course yamaha 1000 times as many
First, I'd like to see some measurements. Where are the actual measurements? Maybe I missed them.
Second, imaging while important is not everything. There is something to be said for a neutral tonal balance especially in the lower midrange. That is where typical floor and ceiling reflections color the sound.
Narrow or wide horizontal directivity can both be made to work in the home environment. At the end of the day, it is what gets to your ears, i.e., speaker directivity combined with the room. No one approach is better. But for sure we want to avoid floor and ceiling reflections.
As a trend, you are right of course, but that's not how I try to design my speakers. I prefer speakers with narrower dispersion horizontally for best imaging in a cramped apartment, with even less dispersion vertically. Of course, this is not the accepted choices, but that's the beauty of DIY, beinga able to choose our own poison, per se.
I cringe a little when I read the status-quo you mention.
Best,
Erik
Patrick, off topic, but were you able to hear the Magico S1s? There's at least one person who raves about them, but I was not so ready to sell a kidney for them. If you have a comment or two I'd love to read.
Best,
Erik
......I've been using 60x40 waveguides for a year now. I won't go back to 90 ever, but my room is only 14 ft wide along the speaker wall so other's may have a need for 90 degrees or more.
PS......I discovered this quite by accident by turing my QSC guides 90 degrees while they were sitting on the midbass modules and WOW.....that was that. But take that for what its worth as I'm done with compression drivers anyways and back to ribbons.
The White Paper has polar maps and useful info about setting various dsp parameters Polars at page 15 and on.
http://www.bang-olufsen.com/ContentV3/downloads/BeoLab90/bang-olufsen-beolab90-whitepaper.pdf
The power amplifiers from the Beolab 90 have the SUMMED power of around 8500 W but they will never be used all at once. The power supply is rated for 250 watt sustained max average, 2000W for 8 seconds and over 18Kw instantaneously for less than a sec. The power consumption is 150 watt continous at idle.
I have an explanation. Actually several.
1) We usually listen to speaker while sitting on a chair or sofa, sitting height typically 40-50cm, which sets our ears at 100-120cm height. Sometimes we stand up, but don't listen carefully then. More often we sit in a row on sofa, not in vertical line on each other's shoulders!
2) Floor and ceiling reflections usually arrive rather late - 5-10ms, which is not so critical for direct sound. Sidewall reflections easily are 1-4ms late and thus affect direct sound more and at more critical bandwith.
3) It is so easy to measure horizontal polars and we are used to wathing them.
4) Vertical directivity problems are relevant practically only for mid-tweeter crossover lobing. Floor and ceiling reflections hide bass-mid discontinuities.
Yes, precisely. Vertical reflections color the direct sound, whereas reflections from sides add to the spaciousness. Our ears are well-positioned to separate reflections arriving from the side from the direct sound. And I am not making this up. These are well-established facts.
I just don't buy any of these explanations or at least they are misguided if true.
1) Producing the same sound across a wide angle horizontally is important in pro-sound applications. What is the angle subtended by the sofa relative to the speaker? 20 degrees, 40 degrees? Depends on the listening distance. But even a properly design cone and dome can get the same sound across the sofa. Why the chase for any particular horizontal directivity?
2) Timing of the reflections is one aspect, direction is another. I'm not sure where you get that side wall reflections are typically 1-4 ms. It depends on the room and setup. But the fact is we are able to separate out sidewall reflections from the direct sound, whereas vertical reflections are perceived as a coloration of the direct sound.
Also, it is so much easier to damp sidewall reflections. Ever tried putting a diffuser on the ceiling or absorption panels on the floor. Imagine how that works out from a home decor point of view.
4) No one is asking for constant vertical directivity. We are only asking for a solution to mitigate the problem of vertical reflections.
There is no doubt that the Beolab90 will perform admirably in many aspects, but I just don't see any reason to salivate over it. More radiating area and top class drivers will give you low distortion and a capability to go loud. DSP power can give you control over directivity, but it would be much more impressive if they used the knowledge we have to solve problems in home listening environments that do matter rather than solving those that matter less.
Floyd Toole et al. authorities are not very much worried about vertical smoothness, they also give definition for early/late reflections. Very often sidewalls are too near the speakers. Vertical dispersion "profile" contributes to total power response too, but other factors are usually more important for final "aural" sound signature- including positioning in the room.
Wide angle vertical measurement is simple to perform, but we don't get much practical info from that. Besides, if done indoors at home the relevance is questionable. Vertical high directivity to mitigate floor/ceiling reflections is a very difficult task, because of wavelenth. It is wiser (or more practical) to place woofer(s) near the floor than make a very tall tower. Perhaps it is just our laziness, that we so seldom see them done or published.
Wide angle vertical measurement is simple to perform, but we don't get much practical info from that. Besides, if done indoors at home the relevance is questionable. Vertical high directivity to mitigate floor/ceiling reflections is a very difficult task, because of wavelenth. It is wiser (or more practical) to place woofer(s) near the floor than make a very tall tower. Perhaps it is just our laziness, that we so seldom see them done or published.
I had a closer look at that speaker's concept and also his acoustic behaviour as published by the designer/manufacturer. Frankly speaking, to me it is a "playing games with people" concept. Maybe this was not intended, but this is what came out IMO.
B&O whitepaper:
http://www.bang-olufsen.com/ContentV3/downloads/BeoLab90/bang-olufsen-beolab90-whitepaper.pdf
Some remarks on peculiarities that led me to this point of view ....
>> Feature: Rotating the 'beam' in 'wide radiation mode'
This part of the handling concept is putting a design burden on the whole speaker because of a merely useless feature: Someone who wants easy listening at a place far from the usual stereo listening zone or sweetspot - e.g. because of having breakfast or reading a newspaper there - is pretty statisfied to use a radiation pattern, that will just not sound too colored at his place.
Surely he/she won't pay attention - say after the 12th day of owning a new speaker ... - to choose the pattern rotation and L vs. R delay properly everytime by fumbling with the remote control, when his/her main attention is to do something else than listen to stereo music (in a properly symmetric setup also due to reflections ...).
>> A Loudspeaker having the opportunitiy to (fine ?) tune the radiation pattern in a usefull manner due to differing room acoustics would indeed provide interesting options e.g. for matching the system's radiation pattern in the highs with different absorption of listening rooms.
Now let's compare the 'wide' to the 'narrow' pattern above say 6Khz:
There is hardly any difference (oops!). As a short description the 'wide' pattern drops to the 'narrow' pattern nearly within one octave (3Khz ... 6Khz). Congratulations from my side, for this engineering masterpiece in pattern control ...
Who has seen decay time plots of rooms more than once knows very well, that those radiation patterns provided are not suited to compensate for typical listening-/livingroom's decay time curves in order to achieve a "recognized" room curve (e.g. according to Bruel&Kjear or Harman) without spoiling the on axis response (*) . Indeed that would have been an interesting design goal, that obviously has neither been considered nor has it been achieved ...
>> A comparable amount of mid and hi range drivers (and belonging signal paths) could also be used, to achieve a suitable vertical to horizontal distribution, to approximate above said room curves and by the same time also a reduction of highly (interaurally) correlated ceiling and bottom reflections especially in the highs, while maintaining tonality of (laterally and contralaterally balanced ...) side reflections. But no technical efforts, options or results can be seen here either to implement e.g. a suitable "vertical vs. horizontal" control of the radiation pattern.
What can indeed be seen is, that high efforts while having strange or at least contradicting design priorities, will also lead to strange results.
But at least we have talked about this speaker, which means it has fulfilled his purpose: Thanks for your attention ...
____________
(*) That is by conventional "equalising" ...
B&O whitepaper:
http://www.bang-olufsen.com/ContentV3/downloads/BeoLab90/bang-olufsen-beolab90-whitepaper.pdf
Some remarks on peculiarities that led me to this point of view ....
>> Feature: Rotating the 'beam' in 'wide radiation mode'
This part of the handling concept is putting a design burden on the whole speaker because of a merely useless feature: Someone who wants easy listening at a place far from the usual stereo listening zone or sweetspot - e.g. because of having breakfast or reading a newspaper there - is pretty statisfied to use a radiation pattern, that will just not sound too colored at his place.
Surely he/she won't pay attention - say after the 12th day of owning a new speaker ... - to choose the pattern rotation and L vs. R delay properly everytime by fumbling with the remote control, when his/her main attention is to do something else than listen to stereo music (in a properly symmetric setup also due to reflections ...).
>> A Loudspeaker having the opportunitiy to (fine ?) tune the radiation pattern in a usefull manner due to differing room acoustics would indeed provide interesting options e.g. for matching the system's radiation pattern in the highs with different absorption of listening rooms.
Now let's compare the 'wide' to the 'narrow' pattern above say 6Khz:
There is hardly any difference (oops!). As a short description the 'wide' pattern drops to the 'narrow' pattern nearly within one octave (3Khz ... 6Khz). Congratulations from my side, for this engineering masterpiece in pattern control ...
Who has seen decay time plots of rooms more than once knows very well, that those radiation patterns provided are not suited to compensate for typical listening-/livingroom's decay time curves in order to achieve a "recognized" room curve (e.g. according to Bruel&Kjear or Harman) without spoiling the on axis response (*) . Indeed that would have been an interesting design goal, that obviously has neither been considered nor has it been achieved ...
>> A comparable amount of mid and hi range drivers (and belonging signal paths) could also be used, to achieve a suitable vertical to horizontal distribution, to approximate above said room curves and by the same time also a reduction of highly (interaurally) correlated ceiling and bottom reflections especially in the highs, while maintaining tonality of (laterally and contralaterally balanced ...) side reflections. But no technical efforts, options or results can be seen here either to implement e.g. a suitable "vertical vs. horizontal" control of the radiation pattern.
What can indeed be seen is, that high efforts while having strange or at least contradicting design priorities, will also lead to strange results.
But at least we have talked about this speaker, which means it has fulfilled his purpose: Thanks for your attention ...
____________
(*) That is by conventional "equalising" ...
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B&O is often bought by people who choose their audio equipment based on what is presented by non-audio lifestyle mags. They often live in houses and condos that are the least usable for listening to music. Therefore B&O makes a lot of attempts to correct problems that the ordinary audio guy doesn't have. And yes, they are quite creative in doing this.
Regards
Charles
^and ^^ Well, this is nothing new under the sun... Most "white paper" pamphlets are just marketing babble. Scientific and pseudoscientific words, phrases and concepts in random order to make the reader "buy it".
But this Beolab 90 is a jubilee showcase. Extravagant form and functionality and sure it has gained lots of publicity. The people at B&O lab aren't dummies and they know physical laws and loudspeaker-in-a-room problems. But they can't break these laws any better than others, even diyers. Unity horns and floor to ceiling arrays etc curiosities have some special features, but also special caveats. I think that Beolab 90 is much better "case" and performer than the previously mentioned Yamaha "soundbar projector".
But this Beolab 90 is a jubilee showcase. Extravagant form and functionality and sure it has gained lots of publicity. The people at B&O lab aren't dummies and they know physical laws and loudspeaker-in-a-room problems. But they can't break these laws any better than others, even diyers. Unity horns and floor to ceiling arrays etc curiosities have some special features, but also special caveats. I think that Beolab 90 is much better "case" and performer than the previously mentioned Yamaha "soundbar projector".
You can't compare the soundbar with the new B&O IMO. Both are using beam steering but they use it for different things.
The sound bar emulates a surround system by generating 5 independant beams of sound that reach the listener via wall reflections in case of left right and rears.
Regards
Charles
The sound bar emulates a surround system by generating 5 independant beams of sound that reach the listener via wall reflections in case of left right and rears.
Regards
Charles
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